Thermoforming of sheet material can be accomplished by heating the sheet material and molding the material while hot by pressing between two half molds, or between a mold and a molding surface. Such thermoforming has been described in U.S. Pat. Nos. 5,928,597 and 6,146,578, for example, which are hereby incorporated by reference. Such processes can be used to form various objects such as automobile headliners, decorative panels, etc.